docs: revert for metadata [skip ci]

Author: awxiaoxian2020

src/site/es/markdown/index.md

@@ -1,6 +1,5 @@
 title: MyBatis 3 | Introducción
-<meta name="author" content="Clinton Begin" />
-<meta name="author" content="Eduardo Macarron" />
+author: Clinton Begin, Eduardo Macarron
 
 ## Introducción
 

src/site/ja/markdown/index.md

@@ -1,6 +1,5 @@
 title: MyBatis 3 | イントロダクション
-<meta name="author" content="Clinton Begin" />
-<meta name="author" content="Iwao AVE!" />
+author: Clinton Begin, Iwao AVE!
 
 ## イントロダクション
 

src/site/ko/markdown/index.md

@@ -1,6 +1,5 @@
 title: 마이바티스 3 | 소개
-<meta name="author" content="Clinton Begin" />
-<meta name="author" content="이동국(한국어 번역)" />
+author: Clinton Begin, 이동국(한국어 번역)
 
 ## 소개
 

src/site/zh/markdown/index.md

@@ -1,7 +1,5 @@
 title: MyBatis 3 | 简介
-<meta name="author" content="Clinton Begin" />
-<meta name="author" content="Nan Lei" />
-<meta name="author" content="Dongxu Wang" />
+author: Clinton Begin, Nan Lei, Dongxu Wang
 
 ## 简介